The Great Stagnation, Football Ball Edition

'Since 2002, panel numbers have roughly halved every four years: 32 in 2002, 14 in 2006 and eight in 2010. Thus, by the 2022 World Cup, players should be kicking a single-panel ball around the pitch.' claimed Ken Bray here. I will call this Brays law 'The number of panels on the World Cup football ball will half every tournament'. This is not quite as epoch defining as Moore's law but still cool I think.

This year according to projections the soccer ball in the world cup should have at most 4 panels. Instead the ball has 6. 50% more panels then you would expect if progress continued at the rate Bray predicted. The Great Stagnation is the belief that things are not improving as quickly as they used to and is used to explain why we still have homeless people but not flying cars.

The number of panels each world cup ball has is found on each balls individual Wikipedia page.

2014 the Adidas Brazuca: 'The ball has been made of six polyurethane panels'

2010 the Adidas Jabulani: 'The ball was constructed consisting of eight (down from 14 in the 2006 World Cup) thermally bonded, three-dimensional panels'

2006 the Adidas Teamgeist:'The Teamgeist ball differs from previous balls in having just 14 curved panels rather than the 32 that have been standard since 1970. Like the 32 panel Roteiro which preceded it'

Fewer panels mean the ball is smoother and should fly more true. The ball flying true involves the interaction of several variables other than the panel number though. The 2010 ball was notorious for wobbly flight for example. For this reason just reducing the number of panels at the expense of the quality of the ball is a bad idea and may explain why Bray's law has failed. Still not being able to make a ball work with fewer panels indicates a technological innovation slow down to me. The aerodynamics of soccer balls and why there is a race to fewer panels is described in Brays article 'A fly walks round a football'.